/toy-payment-engine

Primary LanguageRust

toy payment engine

Some assumptions that were used when building that

  • Account ids are unique
  • Transaction ids are unique per account
  • Dispute only works on deposits since we need to hold funds in dispute
  • Chargeback cannot occur if it leaves account balance negative

Main logic is implemented in account.rs, it describes Account struct that can be modified using actions defined as an algebra. Operations like deposit/withdrawal etc. are encoded in Transaction enum after being from raw csv and validated.

Financial computations are handled by rust_decimal crate that provides operations on decimals without round-off errors unlike typical floating precision types. While rust_decimal is not arbitrary-precision it should cover the case of 4 digits precision and even might be a bit overkill for that if we want to save space.

To run

cargo run -- <path/to/input/file.csv>

To run tests

cargo test

Built & tested with 1.61.0-x86_64-unknown-linux-gnu